A man seen in multiple ISIS propaganda videos speaking with a British accent and beheading Western hostages had his identity revealed in the Washington Post this morning, and yet again the suspect is another case of what I have termed “known wolf” syndrome since he was already known to authorities before engaging in acts of terrorism.

The Washington Post reports:

The world knows him as “Jihadi John,” the masked man with a British accent who has beheaded several hostages held by the Islamic State and who taunts audiences in videos circulated widely online.

But his real name, according to friends and others familiar with his case, is Mohammed Emwazi, a Briton from a well-to-do family who grew up in West London and graduated from college with a degree in computer programming. He is believed to have traveled to Syria around 2012 and to have later joined the Islamic State, the group whose barbarity he has come to symbolize.

But the article goes on to reveal that Emwazi had been detained by authorities not once, but twice:

Emwazi and two friends — a German convert to Islam named Omar and another man, Abu Talib — never made it on the trip. Once they landed in Dar es Salaam, in May 2009, they were detained by police and held overnight. It’s unclear whether the reason for the detention was made clear to the three, but they were eventually deported.

Emwazi flew to Amsterdam, where he claimed that an officer from MI5, Britain’s domestic security agency, accused him of trying to reach Somalia, where the militant group al-Shabab operates in the southern part of the country, according to e-mails that he sent to Qureshi and that were provided to The Post.

Emwazi denied the accusation and claimed that MI5 representatives had tried to recruit him […]

In June 2010, however, counterterrorism officials in Britain detained him again — this time fingerprinting him and searching his belongings. When he tried to fly back to Kuwait the next day, he was prevented from doing so.

The Daily Mail adds that after that June 2010 encounter with law enforcement, Emwazi was put on the UK terror watch list:

They allegedly fingerprinted him and searched his belongings, and he was not allowed to fly back to Kuwait. Emwazi was put on a terror watch list and banned from leaving the UK.

The BBC added that Emwazi was part of a known network of jihadist sympathizers:

We don’t know when the British or the American security services worked out that the masked man in the killing videos was Londoner Mohammed Emwazi.

But we do know that he was a “person of interest” to MI5 going back to at least 2011 because he features in semi-secret court cases relating to extremism overseas and back in the UK.

Nobody in official security circles is going to comment on what they know and why they know it.

Emwazi has been previously described as a member of a network involving at least 13 men from London – and at least two of them were subjected to house arrest control orders or T-Pims. One absconded. The chances of Emwazi ever returning to the UK are vanishingly small.

So yet again, as we’ve seen in practically every recent terrorism case, the suspect was already known to authorities.

I’ve reported here at PJ Media on the long line of “Known Wolf” terror suspects who committed acts of terror:

Yesterday, an interview I had with Erick Stakelbeck aired where I discussed the “Known Wolf” terror phenomenon (the first 11 minutes of the program):

Needless to say, if the currently growing track record of Western authorities missing these “known wolf” suspects is any indication, the next terror case will undoubtedly be a subject already known to law enforcement and intelligence authorities, but sufficient action not taken to stop their terrorism.